
<template>
  <div class="app-container">
    <h2 style="text-align: center;">发布新课程</h2>
    <el-steps :active="1" process-status="wait" align-center style="margin-bottom: 40px;">
      <el-step title="填写课程基本信息"/>
      <el-step title="创建课程大纲"/>
      <el-step title="最终发布"/>
    </el-steps>
    <el-form label-width="120px">
      <el-form-item label="课程标题">
      <el-input v-model="courseInfo.title" placeholder=" 示例：机器学习项目课：从基础到搭建项目视频课程。专业名称注意大小写"/>
      </el-form-item>
      <!-- 所属分类 TODO -->
      <el-form-item label="课程分类">
        <el-select
          v-model="courseInfo.subjectParentId"
          placeholder="一级分类"
          @change="getChildrenSubjectList">
          <el-option
            v-for="oneSubject in oneSubjectList"
            :key="oneSubject.id"
            :label="oneSubject.title"
            :value="oneSubject.id"/>
        </el-select>
        <el-select
          v-model="courseInfo.subjectId"
          placeholder="二级分类">
          <el-option
            v-for="childrenSubject in childrenSubjectList"
            :key="childrenSubject.id"
            :label="childrenSubject.title"
            :value="childrenSubject.id"/>
        </el-select>
      </el-form-item>
      <!-- 课程讲师 -->
      <el-form-item label="课程讲师">
        <el-select
          v-model="courseInfo.teacherId"
          >
          <el-option
            v-for="teacher in teacherList"
            :key="teacher.id"
            :label="teacher.name"
            :value="teacher.id"/>
        </el-select>
      </el-form-item>
      <el-form-item label="总课时">
        <el-input-number :min="0" v-model="courseInfo.lessonNum" controls-position="right" placeholder="请填写课程的总课时数"/>
      </el-form-item>
      <!-- 课程简介  -->
      <el-form-item label="课程简介">
        <tinymce :height="300" v-model="courseInfo.description"/>
      </el-form-item>
      <!-- 课程封面 TODO -->

      <el-form-item label="课程封面">
        <el-upload
          class="avatar-uploader"
          :action="BASE_API+'/oss/file/upload'"
          :show-file-list="false"
          :on-success="handleAvatarSuccess"
          :before-upload="beforeAvatarUpload">
          <img v-if="courseInfo.cover" :src="courseInfo.cover" class="avatar">
          <i v-else class="el-icon-plus avatar-uploader-icon"></i>
        </el-upload>
      </el-form-item>
      <el-form-item label="课程价格">
        <el-input-number :min="0" v-model="courseInfo.price" controls-position="right" placeholder="免费课程请设置为0元"/> 元
      </el-form-item>

      <el-form-item>
        <el-button :disabled="saveBtnDisabled" type="primary" @click="saveOrUpdate">保存并下一步</el-button>
      </el-form-item>
    </el-form>
  </div>
</template>

<script>
  import Tinymce from '@/components/Tinymce'
  import course from '../../../api/edu/course'
  import subject from '../../../api/edu/subject'
  export default {
    components: { Tinymce },
    name: 'info',
    data(){
      return{
        saveBtnDisabled:false,
        courseInfo:{
          cover:"https://yygh-lw.oss-cn-hangzhou.aliyuncs.com/a6388f9d-c161-4814-91e9-1b4976d87e2311.jpg"
        },
        teacherList:[],
        oneSubjectList:[],
        childrenSubjectList:[],
        BASE_API:process.env.BASE_API,
        courseId:''
      }
    },
    created() {
      //获取路由中的id值
      if (this.$route.params && this.$route.params.id) {
        this.courseId = this.$route.params.id
        this.getInfo()
      }
      this.getTeacherList()
      this.getOneSubjectList()
    },
    watch: {
      $route(to, from) { //路由发生改变执行
        if (this.courseId!=''){
          this.courseInfo={}
        }
      }
    },
    methods:{
      getInfo(){
        course.getCourseInfo(this.courseId).then(res=>{
          this.courseInfo=res.data
          this.getChildrenSubjectList(this.courseInfo.subjectParentId)
        })
      },
      handleAvatarSuccess(res){
        //上传成功
        this.courseInfo.cover=res.data
      },
      beforeAvatarUpload(file){
        //上传之前
        const isJPG = file.type === 'image/jpeg'
        const isLt2M = file.size / 1024 / 1024 < 2
        if (!isJPG) {
          this.$message.error('上传头像图片只能是 JPG 格式!')
        }
        if (!isLt2M) {
          this.$message.error('上传头像图片大小不能超过 2MB!')
        }
        return isJPG && isLt2M
      },
      saveOrUpdate(){
        if (this.courseId=='') {
          //保存
          course.addCourseInfo(this.courseInfo).then(res => {
            //提示
            this.$message({
              type: 'success',
              message: "添加课程信息成功"
            })
            //跳转到第二步
            this.$router.push({ path: '/course/chapter/' + res.data })
          })
        }else {
          //更新
          course.updateCourseInfo(this.courseInfo).then(res=>{
            //提示
            this.$message({
              type: 'success',
              message: "更新课程信息成功"
            })
            //跳转到第二步
            this.$router.push({ path: '/course/chapter/'+this.courseId })
          })
          }
      },
      getTeacherList(){
        course.getTeacherList().then(res=>{
          this.teacherList=res.data
        })
      },
      getOneSubjectList(){
        subject.getSubjectList().then(res=>{
          this.oneSubjectList=res.data
        })
      },
      getChildrenSubjectList(id){
        //一级id分类自动传递
        for (let i = 0; i < this.oneSubjectList.length; i++) {
          if (this.oneSubjectList[i].id === id) {
            this.childrenSubjectList = this.oneSubjectList[i].children
          }
        }
      }
    }
  }
</script>

<style scoped>
  .tinymce-container {
    line-height: 29px;
  }
</style>
